william a



1 2 Sheets-Sheet- 1.

W. A. LIGHTH ALL.v Refrigerating Apparatus.

' No. 224,785. Patented Feb. 24, 1880.

[ail n 882s.-

N. PETERS. PHO'ZDJJTHOGRAPIER, WlSRIN 2 Sheets-Sheet 2;

Patenied Feb. 24, 1880.

In venlma amw will? 08S as:

UNITED STATES PATENT OF ICE.

1 WI LIAM A. LIGHTHALL, or BROOKLYN, ASSIGNOR TO HIMSELF, wrLLiAM n.JEWELL, nnwn. e- RURRER, Ann CHARLES M. HASTINGS, OF NEW YORK, N. Y.

REFRIGERATINQG APPARATUS.

SPECIFICATION forming part of Letters Patent No. 224,785, dated February24, 1880.

Application filed July 26, 1879.

paratus, of which the following is a specification, reference being hadto the accompanying drawings, forming part of the same.

Figure l is a perspective'view of my apparatus, showing one side and endof the same;

and Fig. 2 is a similar view, showing the opposite side and end of thesaid apparatus.

My'invention relates to mechanism whereby cold is produced by theexpansion of com- 5 pressed air.

The mechanism to which my invention is applied consists, ordinarily, ofan air-compressing pump, G, driven by a steam-engine, A, or other motor;a cooling-receptacle, H, to receive the compressed air from the pump 0;an airexpanding cylinder and piston, D, in which the compressed airconducted from H is permitted to expand against resistance, therebyparting with its heat and becoming chilled; a refrigerator, F, intowhich the cold expanded air is conducted from D, and in which the saidcold air is utilized in the production of frigorific effects; acooling-receptacle, G, into which the air is conducted from therefrigerator F,

0 where, still having a low temperature, it is of substantially similarconstruction, and con- 4 by it circulating around the tubes.

employed to chill the water that is used to cool the heated compressedair in H, and from which the air is conducted back to thecompressing-pump G, the air in the apparatus being used over and overagain, instead of being discharged after producing its frigorificeffects .by expansion, and a new supply taken in by the compressing-pumpfrom the external atmosphere.

The several receptacles F, G, and H may be sist of a case in which isarrangeda series of tubes, the air passing through the tubes, and thefluid to act upon the air or be acted upon Suitable pipe-connections areprovided for conducting the air to the several parts, as shown in thedrawings. A suitable apparatus is also provided for circulating both thewater used for cooling the air heated by compression and the-fluid thatis cooled by expanded cold air.

Thisapparatus is shown in Fig. l of the drawings, in which K is a commonsteam-cylinder and piston.

J andJ are two force-pumps, J being designed to circulate through E andG the water for cooling the compressed air, and J to circulate thenon-congealable fluid that has been chilled in F. r

A more particular description of the abovenamed apparatus is deemedunnecessary, as, I

do not claim it.

I will now proceed to describe parts of the machine which are of myinvention.

It is important that a very uniform degree of compression of the air orair-pressure should be maintained in the apparatus, in order that theconsumption of power and the consequent rate of refrigeration should beuniform. The air being used over and over again, if there is absolutelyno loss of air by loose joints or otherwise, there will necessarily bethis uniformity after the apparatus is once properly charged; but lossof air will, practically, always take place to a greater or less extent.In, order to supply this loss, I have provided an automatic equalizingapparatus consisting of the valve-chamber I, which may be a small hollowcylinder strong enough to bear the air-pressure in. the apparatus. Tothis cylinder the expanded air is conducted, by a pipe, 2', from thereceptacle in which the air is expanded, and from it the air isconducted, by the pipe j, to the com pressorO, so that the air, on itsway from the refrigerator back to the compressor, passes through thiscylinder. The cylinder is provided with two valves, is and one openingin and the other out, which are controlled by springs. These springs areso adjusted that when the air pressure in the cylinder rises above acertain degree the valve 70 will open and permit escape of air until thepressure falls below the tension of the spring; and if the pressure inthe cylinder falls below the ordinary pressure of the externalatmosphere to a certain degree, valve 70 will open and permit theadmission of air. The valves thus act automatically to regiila'tewithout the escape of air.

which is being subjected to alternate compression and expansion in theapparatus, and the consequent degree of air-pressure which may bedesired.

The moisture contained in the air, as it is introduced into theapparatus from the external atmosphere, has to be removed as itcondenses; otherwise it is liable, by freezing, to interfere with theaction of the compressingpump and the expander. I provide an apparatuswhereby, as this moisture condenses in the receptacle H by contact withthe surfaces of the pipes therein, that are chilled by the cold waterflowing around them through that receptacle, it may be drawn off anddischarged As it condenses, the Water, of course, finds its way downtothe bottom of the receptacle H. To be able to draw off this waterwithout allowing the escape of air, I provide a closed receptacle, J,which must have the requisite strength to resist the air-pressure in theapparatus. A pipe, g, leads from the bottom ofH to J, which pipe isprovided with a stop-cock, h. The receptacle J has an escape-pipe, whichis also pro vided with a stop-cock, h. When h is open and h closed, thewater, as fast as it is formed by condensation, will run down from Hthrough 9 into J 5 then, by closing or nearly closing h and opening h,the water may be discharged from J without the escape of air, care beingtaken to close one or both of the cocks just before or at the instantthe water is all discharged.

The general operation of this description of 3 5 compressed-airrefrigerator, being well-known, need not be particularly described, andthe operation of the above-described air-regulator and device fordrawing off the water of condensation is obvious from the descriptiongiven.

What 1 claim as new, and desire to secure by Letters Patent, is

1. The combination, in a pneumatic refriger- 71., all constructed andoperating as and for the purpose described.

55 Subscribed by me this 24th day of July, 1879.

'WM. A. LIGHTHALL.

Witnesses:

M. F. CLIFTON, B. S. CLARK.

